Our Buildings and Grounds guys would like a simple screen that displays some weather on a single page. Humidity, Temp, Wind, Rainfall, 5 day forecast and a radar if possible.

I have a spare rPi hanging around after upgrading two library catalog machines to rPi4 so I could use those, just not sure where to start on the process.

Make the rpi boot unattended into a browser preferably in kiosk mode. Make a html file locally on your system and set that up as the start page (and only page). Hotlink to images or other info. If you need to scrape or connect to other services you need to install a local webserver and have php, python or whatever script do that.

Have the page reload itself every 5 minutes or whatever suitable.

PS. If you have infrastructure in place it might be better to have the rpi pull information from another webserver. Then you have no code or anything on the rpi and it's easier to change information because it's on another server and also easy to add another rpi or replace it if it breaks.